linux-stable.git/tools/testing/selftests/bpf/progs/verifier_live_stack.c, branch linux-rolling-stable Linux kernel stable tree bpf: test the correct stack liveness of tail calls 2025-11-22T01:45:30+00:00 Eduard Zingerman eddyz87@gmail.com 2025-11-19T16:03:55+00:00 8f7cf305a15eec663d5084e417f4773f1ef24e23 A new test is added: caller_stack_write_tail_call tests that the live stack is correctly tracked for a tail call. Signed-off-by: Eduard Zingerman <eddyz87@gmail.com> Signed-off-by: Martin Teichmann <martin.teichmann@xfel.eu> Link: https://lore.kernel.org/r/20251119160355.1160932-5-martin.teichmann@xfel.eu Signed-off-by: Alexei Starovoitov <ast@kernel.org> 
A new test is added: caller_stack_write_tail_call tests that the live
stack is correctly tracked for a tail call.

Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Martin Teichmann <martin.teichmann@xfel.eu>
Link: https://lore.kernel.org/r/20251119160355.1160932-5-martin.teichmann@xfel.eu
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
selftests/bpf: test cases for callchain sensitive live stack tracking 2025-09-19T16:27:24+00:00 Eduard Zingerman eddyz87@gmail.com 2025-09-19T02:18:45+00:00 fdcecdff905cf712279d3ba72ec8ac7bc02be7ff - simple propagation of read/write marks; - joining read/write marks from conditional branches; - avoid must_write marks in when same instruction accesses different stack offsets on different execution paths; - avoid must_write marks in case same instruction accesses stack and non-stack pointers on different execution paths; - read/write marks propagation to outer stack frame; - independent read marks for different callchains ending with the same function; - bpf_calls_callback() dependent logic in liveness.c:bpf_stack_slot_alive(). Signed-off-by: Eduard Zingerman <eddyz87@gmail.com> Link: https://lore.kernel.org/r/20250918-callchain-sensitive-liveness-v3-12-c3cd27bacc60@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> 
- simple propagation of read/write marks;
- joining read/write marks from conditional branches;
- avoid must_write marks in when same instruction accesses different
  stack offsets on different execution paths;
- avoid must_write marks in case same instruction accesses stack
  and non-stack pointers on different execution paths;
- read/write marks propagation to outer stack frame;
- independent read marks for different callchains ending with the same
  function;
- bpf_calls_callback() dependent logic in
  liveness.c:bpf_stack_slot_alive().

Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20250918-callchain-sensitive-liveness-v3-12-c3cd27bacc60@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>